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57 Tbird Fordo conversion to 3 speeds forward in drive

June 20 2011 at 6:33 PM

Mark H  (Login 65hdtp)
from IP address 69.109.165.135

 
I am looking to install an FMX valve body, shift detent (rooster comb) and modulator valve in a 57 Tbird 312 V8 Fordomatic. This is to have 3 speeds forward in the Drive position. Normally it starts in second unless you floor the gas pedal, then it will start off in first. Is there a difference between a floor shift FMX shift detent and a column shift FMX shift detent. If so which one should I use? Any other pointers?

 
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Stuart Anderson
(Login stuart40a)
Forum Moderator
71.17.81.2

Sorry

June 20 2011, 7:22 PM 

That's a nogo project.

To turn it into a true 3 speed the transmission must have an over/run clutch for 1st. gear.

Just adding and FMX valve body won't do it.


 
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Mark H
(Login 65hdtp)
69.109.165.135

Re: Sorry

June 20 2011, 7:51 PM 

Stuart,
I found this info on the Yblocksforever.com forum...is it in correct?

"You can if your FOM has a one-way clutch in the middle of the transmission. This is found in the ones that will downshift to 1st when you floor the throttle from a dead stop. You also have to use the FMX detent, sometimes referred to as a "rooster comb", and drill and tap the back of the case for the vacuum modulator."

 
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Stuart Anderson
(Login stuart40a)
Forum Moderator
71.17.81.2

Yes but

June 20 2011, 8:17 PM 

Yours is a Fordomatic, not Cruisomatic.

Yours does not have a one way / over run clutch.

 
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Mark H
(Login 65hdtp)
69.109.165.135

Re: Yes but

June 20 2011, 8:31 PM 

Well, you may have saved me from a big mistake. I have a 57 Fordomatic Transmission Manual and don't see anything labeled as a one-way clutch in the diagrams. It does mention a "forced downshift" to 1st when floored under 16MPH. Here is the rest of the instruction I found:

"You need a valve body from a COM of the mid '60s to mid '70s. The post '67s will be FMXs. Look for a vacuum modulator on the back of the case on the shift lever side. Pre-FMXs will have a shift indicator on the dash with two drive ranges and a low. In one drive range it takes of in 1st, in the other it takes off in 2nd. FMXs have a D-2-1 shift pattern, always take off in 1st. You also need the detent from the shift lever inside the case. Some call it a "rooster comb", it does look like one. The valve body and detent are installed in your trans, they're bolt-ins. The detent is irksome, the spring loaded ball keeps wanting to pop out of its bore and roll under the bench or into a floor drain. Some FMXs have a rounded pin instead of the ball, it's a lot easier to install. The valve body may block the passages to the rear pump, but no matter. I ususally take the outer gear of the pump out to reduce drag, leave the inner one in as a spacer. You can no longer push start the car. You have to drill and tap the case to accomodate the vacuum modulator, which is connected to intake manifold vacuum. Use the COM case to measure the location of the hole. Your '57 water cooled should have the internal one way clutch, so should be OK. Your shifter may not have enough travel to reach manual 1st, can probably be reworked to do this, but for normal driving you don't need manual low anyway. I have this in my '56 Bird and it works well. Really helps it step away from stoplights in city traffic. Less load on the engine, less load on the transmission, so less heat generated. Too bad Warner Gear didn't do this with the very first FOMs, would have eliminated a lot of bad press in the early '50s Fords. The modulator also eliminates the "bang" you get when you shift from N to Dr or R."

 
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Stuart Anderson
(Login stuart40a)
Forum Moderator
71.17.81.2

Re: Yes but

June 20 2011, 8:40 PM 

The one way clutch came into service in 1958.


Your shift quadrant will show, PRNDL.

1958 quadrants have, PRNdDL.
These are also know as "GREEN DOT" transmissions.
Unless you can come up with a 58 or newer you are SOL.

 
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Mark H
(Login 65hdtp)
69.109.165.135

Re: Yes but

June 20 2011, 8:53 PM 

Thanks Stuart. I will call the project off. Thought it would be an easier and less expensive way to deal with the shifts. A 312 Yblock with new aluminum heads, 3x2 94's, headers, MSD, etc. is about ready to go back in the Tbird.

 
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Jon Mortrud
(no login)
64.90.68.27

Can Valve Body be modified

June 9 2012, 1:00 PM 

Since the VB has the ability to select 1st gear, can the valve body be modified and drilled or even externally circuited to get 1st out of the hole or... since the VB never had the circuit to do a controlled 1-2 shift, does the VB not have the spools to do a 1-2 shift?

 
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Stuart Anderson
(Login stuart40a)
Forum Moderator
71.17.81.131

Re: Can Valve Body be modified

June 9 2012, 1:06 PM 

Since the VB has the ability to select 1st gear, can the valve body be modified and drilled or even externally circuited to get 1st out of the hole or... since the VB never had the circuit to do a controlled 1-2 shift, does the VB not have the spools to do a 1-2 shift?







This thread is almost 1 year old, but to answer your question. No.

 
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